Sangamo bulks up in cell therapy with TxCell acquisition

Hopes to start cell-based immunotherapy trials next year

Sangamo has agreed a €72m deal to take control of French biotech TxCell, eyeing a regulatory T cell (Treg) platform that it says would accelerate its plans to enter the cell therapy market.

Sangamo’s zinc finger nuclease (ZFN) gene-editing technology is already being used to create chimeric antigen receptor T cell (CAR-T) cancer therapies under a $3b-plus deal with Gilead’s Kite unit, signed earlier this year, and it also has an early-stage programmes in stem cell therapies for blood diseases and off-the-shelf (allogeneic) CAR-Ts for cancer.

By acquiring TxCell, Sangamo thinks it will be able to start trials of cell-based immunotherapies as early as next year, headed by TxCell’s TX200 candidate to prevent graft rejection in solid organ transplant patients and with follow-up projects in other autoimmune diseases and inflammatory such as Crohn’s disease and multiple sclerosis. It plans to a start a phase I/II trial in Europe before the end of 2019.

TxCell’s spin on cell therapy us to use Treg cells modified with a CAR to induce and maintain tolerance to antigens, and it says it is in pole position to start trials of a CAR-Treg in humans. It’s a different approach to CAR-T in cancer, where the effector T cells are engineered to attack cells expressing specific, tumour-associated antigens.

CAR-T is becoming a commercial reality with approvals for therapies from Novartis and Gilead/Kite and dozens of other candidates coming through the pipeline, but TxCell reckons its focus on autoimmunity and inflammation puts it in a new and unpopulated cell therapy category.

If successful in trials, the CAR-Tregs could provide a long-acting, highly targeted alternative to drugs like TNF inhibitors, that make billions of dollars in sales every year but have to be given regularly and can cause side effects such as infections.

While Sangamo will focus on TxCell’s existing pipeline at the outset, the company says it will move quickly ahead with studies looking at applying ZFN gene editing to “develop next-generation autologous and allogeneic CAR-Treg cell therapies for use in treating autoimmune diseases.”

ZFN is a gene-editing approach that uses a DNA-cutting nuclease enzyme attached to zinc finger -binding proteins to recognize and edit specific sequences of DNA. Other techniques include CRISPR/Cas9 - used by Novartis and Juno - and Cellectis’ favoured TALENS.

"We are thrilled to announce this proposed acquisition which would combine TxCell's Treg expertise with our ex vivo gene editing capabilities, positioning Sangamo as a leader in the emerging field of CAR-Treg cell therapy," said Sandy Macrae, Sangamo’s chef executive.

“We believe CAR-Treg therapies will prove to be as exciting for immunology as CAR-T has been for oncology.”